26 The Ornithology of Chester County 
accomplished good work in the vicinity of Berwyn. 
In 1901, the writer of this sketch published a sec- 
tional bird census, taken at Berwyn. ‘This was the 
first List from the eastern border and embraced only 
the breeding birds; it was followed by a similar one 
in 1915, showing the slight changes in the number 
of individuals in the same area over a period of years. 
In consideration of the popular character of the 
foregoing and for the sake of brevity, I have, where 
ever possible, used the common English ‘book’ 
names of the species in preference to the scientific 
or technical terms usually employed. In many in- 
stances these names have been in use for a long time 
in this section; also, not being subject to the laws of 
priority, they are less liable to change, and all are 
perfectly intelligible to the average English-speaking 
ornithologist. Many of the names have the addi- 
tional merit of perpetuating the vernacular of our 
Colonial forefathers, to whom the appellation con- 
veyed some real or fancied characteristic of the 
species, and they are altogether most expressive both 
in prose and poetry. 
The ornithological literature of the county is 
large, I regret that it is not feasible to include a 
complete bibliography; but reference to the more 
important contributions appear in the annotated 
catalogue of species. I am indebted to the follow- 
ing persons for biographical notes or portraits: W. 
L. Baily, Gilbert Cope, Ruthven Deane, Watson W. 
Dewees, Wm. B. Evans, J. Comly Hall, Prof. J. 
W. Harshberger, Rev. W. H. Hazard, Mrs. Ber- 
nard A. Hoopes, J. P. Norris, Jr., Chas. W. Palmer, 
